The selected stone protective agent must have better protection effect. You must consider the protection and decoration effects produced by different stone surface conditions. One important principle when selecting is that whatever the grade of the protective agent, having a test on part before large construction area. Make sure the effect then use in large area. It can avoid the bad maintenance effect caused by the mismatching and incompatibility of stone quality and protective agent. Detailed selecting methods can be categorized simply as follows:



1. Stone with smooth face can choose the kind of stone protective agent that can add the glossiness to stone.



2. If the decorative effect requires deepening the stone color, choose the brightening stone protective agent.



3. To keep the original appearance of stone should choose primary color stone protective agent.



4. Adopt wet combining installation, the underside of stone should choose the kind of stone protective agent that won't affect the adherence fastness between stone and cement mortar.



5. In considering the environmental protection, when working in the confined space, choose the aquosity protective agent or protective agent without volatile organic solvent.



6. The surface of stone or the dry-hang stone surface, choose waterproof protective agent or water-repellent protective agent.



7. Always contact with oil, choose oil-repellent protective agent.



8. When ambient air temperature is too low, aquosity protective agent can not be used as it will frost. At this time should choose oil protective agent. Pay attention to fire prevention when carry out construction.